LED photo sensor (CB6858E)

In the figure we have the way to use a common LED as a light sensor. The operational power supply must be symmetrical. Other operatives can be used.

Lamp Control (CB25902E)
This low-current control circuit has a lamp as a load, but can have other types of devices, such...
Varicap Beat Oscillator (CB25649E)
The varactor or varicap diode tunes the signal for listening to SSB signals on a common receiver. The...
18 V x 1 A Power Supply (CB836E)
This power supply is not protected from shorts in the output. Output voltage is given by the...